The subject invention generally relates to an integrated medication delivery system for delivering medication to a patient. The integrated medication delivery system is primarily used throughout the medical profession to deliver pain control medication and other medications intra-operatively, subcutaneously, and percutaneously to the patient to the patient after a surgical, or some other medical, procedure.
Medication delivery systems are known in the art. As indicated above, medication delivery systems are used to deliver pain control medication and other medications intra-operatively, subcutaneously, and percutaneously to a patient after a surgical, or some other medical, procedure.
Conventional medication delivery systems are deficient for one reason or another. For example, U.S. Pat. No. 5,807,075 to Jacobsen et al. discloses a conventional medication delivery system that includes a base housing and a cassette. The base housing of the ""075 patent houses electronic components, such as an electric motor, a power source, and an electronic controller, and the cassette of the ""075 patent interacts with a supply of the medication to deliver the medication to the patient. This medication delivery system is deficient because the supply of the medication is not integrated into the cassette. That is, the cassette does not house the supply of the medication. Instead, the supply is external to the medication delivery system. This medication delivery system is also deficient because the base housing and the cassette are not properly integrated. As such, the complete medication delivery system, having the base housing and the cassette, cannot be simultaneously sterilized prior to use of the system. Instead, the base housing and the cassette require separate sterilization. Furthermore, because the base housing and the cassette are not integrated, the cassette must be mounted to the base housing which requires additional assembly by a surgeon or some other medical assistant. This additional assembly is time consuming and is often inconvenient for the surgeons and medical assistants.
A further example of a conventional medication delivery system is disclosed in U.S. Pat. No. 4,650,469 to Berg et al. This patent discloses a medication delivery system that includes a control module and a reservoir module removably connected to the control module. The control module includes a pump mechanism, valves, a power source, electronic controls, and the like, and the reservoir module includes a container that supplies the medication to be delivered to the patient. Although the medication delivery system disclosed in the ""469 patent connects the control module and the reservoir module, this medication delivery system is deficient in that, once connected, the control module and the reservoir module cannot be simultaneously sterilized. The modules cannot be simultaneously sterilized because, as described at column 11, lines 22-28, one of the valves in the control module closes the fluid connection (the tube 22) between the control module and the reservoir module at all times. That is, the ""469 patent does not include a device, such as an actuator, to prevent the valves from closing on this fluid connection. As such, a sterilization fluid, such as ethylene oxide (EtO) gas cannot flow into both the control module and the reservoir module once these modules are connected.
The conventional medication delivery system disclosed in the ""469 patent is also deficient because it relies exclusively on a motor and a cam shaft to move the valves from the open position to the closed position when delivering the medication to the patient. This medication delivery system does not incorporate an additional biasing device to ensure that the valves are biased into the closed position if the motor, gear, cam shaft, or power supply fails. Without such an additional biasing device, this system""s ability to prevent the inadvertent delivery of the medication to the patient in the event of one of the above failures is compromised. Instead, this medication delivery system relies only on the motor and the cam shaft to allow or to prevent delivery of the medication, and reliance on these two components is insufficient.
Other conventional medication delivery systems are also deficient for a multitude of other reasons. For instance, these conventional systems do not incorporate port assemblies that adequately control the flow of medication throughout the system. In these conventional systems, a single port assembly does not enable various medical fluids to flow into, from, and within the system. Conventional medication delivery systems also do not provide detection systems that adequately determine when a medication delivery system is realizing a blockage in the flow of medication to the patient or that adequately determine when a supply in the medication delivery system has been depleted. The detection systems in the prior art medication delivery systems do not make optimum use of the position of the tubes that carry the medication relative to the position of the electronic controller. Conventional medication delivery systems also do not provide a testing access port that allows manufacturers to confirm operation of the medication delivery system after assembly, and prior to use, of the system. As such, the operation of many prior art medication delivery systems cannot be confirmed prior to shipment to medical professionals for use. Conventional medication delivery systems are also not ideal for carrying. Some prior art systems do not even include a carrying strap. As such, the patient cannot be easily treated outside of a hospital or other medical facility, the patient is prevented from being ambulatory. Other medication delivery systems in the prior art that do include some form of carrying strap do not make carrying convenient because, in these systems, the carrying strap is not conveniently stored in a storage cavity of the system. That is, the carrying strap is not integrated into the system itself for easy access by the patient. The medication delivery systems of the prior art are also not easily controlled. That is, there is not method associated with these systems that effectively controls an amount of the medication to be delivered to the patient. The prior art methods for controlling the amount of medication that is to be delivered to the patient are deficient because these methods require constant attention, require complicated setup and monitoring by the surgeon or other medical professional, and may even risk the health and safety of the patient. Other conventional medication delivery systems do not have electronic controllers, specifically specialized circuitry incorporated into the controller, that adequately prevent too much medication from being delivered to the patient in the event of failure of certain mechanical components. Also, the electronic controllers and circuitry of other conventional medication delivery systems are not suitably designed to maximize the conservation of power and to prevent the entire medication delivery system from being reset by removing and replacing the power source, e.g. a battery.
Due to the deficiencies in conventional medication delivery systems, including those described above, it is desirable to provide a novel medication delivery system that is appropriately integrated for simultaneous sterilization. It is also desirable to provide a novel medication delivery system that overcomes the other deficiencies identified above in the prior art.
An integrated medication delivery system is disclosed. The medication delivery system delivers medication to a patient. The medication delivery system is primarily used to deliver pain control medication and other medications intra-operatively, subcutaneously, and percutaneously to the patient after a surgical, or some other medical, procedure. The medication delivery system according to the subject invention is suitable for complete sterilization by a sterilization fluid.
To accomplish complete sterilization, the medication delivery system includes a base housing and a medication reservoir. The medication reservoir is disposed about the base housing for storing the medication that is to be delivered to the patient. As such the medication reservoir, i.e., the supply of the medication, is integrated with the base housing.
The medication delivery system includes a pump assembly for delivering the medication to the patient. More specifically, the pump assembly, which is supported by the base housing, includes a pump housing having a pump inlet and a pump outlet. The pump inlet and the pump outlet alternate between an open and a closed state to deliver the medication the patient. A port extends from the base housing and is in fluid communication with the medication reservoir and the pump assembly during sterilization. As such, the port provides access for the sterilization fluid to flow into the medication reservoir and the pump assembly.
The medication delivery system further includes an actuator disposed in the base housing. The actuator operatively engages the pump inlet and the pump outlet to retain both the pump inlet and the pump outlet in the open state during sterilization. As a result, the sterilization fluid can penetrate into the medication reservoir, the pump inlet, the pump housing, and the pump outlet to completely sterilize the medication delivery system. That is, because of the actuator, the complete medication delivery system of the subject invention, including the base housing, the pump assembly, and the medication reservoir can be simultaneously sterilized prior to use of the system. Also, because the medication reservoir is disposed about and properly integrated with the base housing, the supply of the medication is not external to the rest of the medication delivery system, and the medication delivery system does not require additional assembly by a surgeon and the like prior to use.
The pump assembly for the medication delivery system also serves to prevent the inadvertent delivery of the medication to the patient. In addition to the pump housing, the pump inlet, and the pump outlet, the pump assembly may further include, depending on the particular embodiment, first and second pinch levers and at least one biasing device.
The first pinch lever is disposed at the pump inlet and is moveable between an open position and a closed position to control a flow of the medication into the pump housing through the pump inlet. The second pinch lever is disposed at the pump outlet and is moveable between an open position and a closed position to control a flow of the medication from the pump housing through the pump outlet. A motor, which operatively engages the first and second pinch levers, is included to move the first and second pinch levers into the open position such that the medication can delivered to the patient.
The biasing device engages at least one of the first and second pinch levers and works in conjunction with the motor to normally bias at least one of the first and second pinch levers into the closed position during delivery of the medication to the patient. This maintains at least one of the first and second pinch levers in the closed position during a failure of the motor thereby preventing the inadvertent delivery of the medication to the patient. As a result, the medication delivery system of the subject invention does not exclusively rely on the motor to move the valves from the open position to the closed position when delivering the medication to the patient. That is, the biasing device ensures that the first and second pinch levers are biased into the closed position even if the motor, or other mechanical components, such as a gear, cam shaft, or power supply, fails. With the biasing device, the subject invention guarantees prevention of the inadvertent delivery of the medication to the patient in the event of one of the above failures.
A port assembly for the medication delivery system may also be included to enable various fluids, such as the sterilization fluid and the medication, to flow into, from, and within the medication delivery system. The port assembly includes an elongated housing and a plunger disposed within the housing. The plunger is moveable within the housing between an off-position, a fill-position, and a fluid delivery-position. The flow of the fluids into, from, and within the medication delivery system is controlled and modified depending on the position of the plunger. As such, the port assembly provides adequate control of the flow of medication throughout the medication delivery system.
The subject invention further provides a blockage detection system for the medication delivery system. Utilizing an electronic controller, a detection film, and a medication outlet tube, and relying on expansion of the medication outlet tube in response to increased pressure in the medication outlet tube, the empty detection system detects a blockage in the flow of the medication to the patient. The empty detection system adequately determines when the medication delivery system is realizing a blockage. To accomplish this, the empty detection system makes optimum use of the position of the medication outlet tube relative to the position of the electronic controller. The detection film may be replaced with a coating applied to the medication outlet tube that activates the electronic controller.
The subject invention further provides an empty detection system for the medication delivery system. Utilizing the electronic controller, the detection film, and a medication inlet tube, and relying on the collapsibility or contraction of the medication inlet tube in response to variations in pressure in the medication inlet tube that result from a lack of flow of the medication, the empty detection system detects when the supply of the medication has been depleted. To accomplish this, the empty detection system makes optimum use of the position of the medication inlet tube relative to the position of the electronic controller. As in the empty detection system, the detection film in the empty detection system may also be replaced with a coating applied to the medication inlet tube that serves to activate and deactivate the electronic controller.
After assembly of the medication delivery system, the subject invention can be tested using a testing instrument. To accomplish testing of the medication delivery system, at least one testing access port is defined within the base housing. The testing access port is aligned with at least one of the pump inlet, the pump outlet, and the actuator to provide access for the testing instrument. The testing instrument effectively disengages the actuator from the pump inlet and the pump outlet such that they can alternate between open and closed states and the operation of the medication delivery system can be testing with an operable pump assembly. The testing access port, incorporated into the base housing, allows the manufacturer to confirm operation after assembly, and prior to use, of the medication delivery system.
The medication delivery system of the subject invention is also ideal for carrying by the patient. A carrying strap is mounted within the base housing for the carrying of the medication delivery system by the patient. More specifically, carrying strap is at least partially disposed in an integral storage cavity that is defined within the base housing. The carrying strap at least partially extends from the integral storage cavity to interact with the patient for carrying the medication delivery system. The carrying strap and integral storage cavity of the subject invention enable the patient to continue easy treatment outside of a hospital or other medical facility. As a result, the patient can remain ambulatory. Disposing the carrying strap in the integral storage cavity makes carrying the medication delivery system of the subject invention a convenient experience for the patient as the carrying strap is always easily accessible.
The subject invention further includes a method of controlling the medication delivery system. The method includes the step of selecting the amount of the medication that is to be delivered to the patient in accordance with a first set of explanatory indicia on a removable overlay label. Next, the system is locked such that the selected amount of the medication to be delivered to the patient is unable to be modified. After the system is locked, the removable overlay label is removed to reveal a patient label. Then, the medication delivery system is operated in accordance with a second set of explanatory indicia on the patient label. This method effectively controls the amount of the medication that is to be delivered to the patient and also provides for easy control and programming of the medication delivery system. As a result of this method of controlling the medication delivery system, the patient does not need to constantly pay attention to and maintain the medication delivery system. Also, set-up of the medication delivery system is not complicated and monitoring of the medication delivery system is not required such that the health and safety of the patient is not compromised.
The subject invention also includes the electronic controller and specialized circuitry incorporated into the electronic controller for various reasons. For instance, some circuitry is targeted to prevent too much medication from being delivered to the patient if certain mechanical components fail. Other electronic design features of the electronic controller of the subject invention are targeted to conserve power throughout the medication delivery system and to prevent the entire medication delivery system from being reset upon the removal or replacement of the power source.
Accordingly, the subject invention provides an integrated medication delivery system that overcomes the deficiencies in the prior art, including those described above.